# IBC: Traveling Wave-Tube Simulation

The code for IBC(Interactive-Beam-Circuit) treats traveling-wave tube behavior from linear to fully non-linear levels. Applications range from communications to pulsed high power. The novel advances of IBC are the use of many particles with particle-in-cell(PIC) techniques for the electron beam space-charge effects, and displaying the motion of the whole beam.

The slow-wave circuit is approximated by a discrete transmission line that has the same phase velocity and impedance as the laboratory model. There are input and output sections(not necessarily matched) and flexible attenuation specifications (location, taper and value).

The beam motion is axial only, with radially uniform dc density and velocity. The transverse space-charge effects are put in with a plasma frequency reduction factor (one radial mode) by modifying the solver for the space-charge potential. The code runs interactively in real time, displaying many diagnostics simultaneously or separately, such as electron velocities (V_x - x phase space), charge density, beam current driving terms (charge and/or current), circuit voltage, current and power, space-charge field and circuit loss. The units are MKS. The normalized parameters translate readily to those used by J.R. Pierce ( Traveling-Wave Tubes , D. Van Nostrand, 1950).

Hardware/Operating System Requirements: The PC version runs on IBM compatibles with 512K, EGA/VGA color graphics and MS-DOS 3.0 or greater (math coprocessor recommended). The X version runs on UNIX workstations or other platforms that support X Windows.

Compiler: Microsoft C 5.0 or higher for PC. Any C compiler with the Xlib libraries for the X version. FORTRAN 77 compiler for the FORTRAN version.

Versions Available: MS-DOS (IBM compatibles) and X Windows - UNIX

Distribution Media: One 3.5'' DS/HD diskette for the PC version and one 3.5'' DS/HD diskette for the X version. Both in MS-DOS format.

Source Code: Yes, except WinGraphics

Object Code: Only WinGraphics display manager (PC version)

Materials and Handling Fee: $125.00 Documentation is included with the disk: Installation notes and input file examples available separately for\$5.00.

Additional Documentation: C.K. Birdsall and A.B. Langdon, {\em Plasma Physics via Computer Simulation,} McGraw-Hill (1985) and Adam Hilger (1991) which includes an ES1 disk. May be ordered from any bookstore, with ISBN number(0-07-005371-5).

Special Licensing/Distribution Restrictions: when you order this software, you will receive a Software License Agreement. This license must be signed and returned to: Professor C.K. Birdsall, EECS Department, The University of California, Berkeley, CA 94720. We will be glad to send you a copy for perusal prior to the actual purchase of the software. Contact the ILP Software Office (510) 643-6687 to request an advance copy, or access ilpsoft.berkeley.edu for anonymous ftp.

Support: We cannot guarantee assistance if the simulations are used in nonstandard ways. We have used the simulations at Berkeley for both education and research and found the codes to be relatively stable. A Plasma Device Simulation Simulation User's Group has been formed, with occasional newsletters and workshops. To join, contact the Plasma Theory and Simulation Group, c/o Professor C.K. Birdsall, EECS Department, The University of California, Berkeley, CA 94720. (510) 643-6631, or send electronic mail to ptsg@diva.Berkeley.EDU.

Foreign Distribution: Yes.